Incorporation of fusible links into an integrated circuit design is a well-known method of providing for the alteration of fabricated IC devices to repair defects. The method typically includes the use of electrical power or laser irradiation to open a fusible link fuse. Other methods used to alter IC devices include design revision and focused ion beam (FIB) modification, both of which generally involve considerable expense.
The severing of fusible links is a destructive process that is used to remove circuit elements from active use. Thus, metal fuses, for example, typically reside near the surface of the device (at an upper interconnect level) so that they can be blown without impact to other materials or circuit elements nearer to the substrate. Collateral damage from the fuse-opening process is a reliability concern that may result in decreased device yield and/or early failure after delivery to a customer.